linux-kernel - [PATCH 05/26] usb: gadget: f_ecm: eliminate abuse of ep->driver data

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Date:	Tue, 15 Sep 2015 16:26:48 +0200
From:	Robert Baldyga <r.baldyga@...sung.com>
To:	balbi@...com
Cc:	gregkh@...uxfoundation.org, linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org, b.zolnierkie@...sung.com,
	m.szyprowski@...sung.com, andrzej.p@...sung.com,
	Robert Baldyga <r.baldyga@...sung.com>
Subject: [PATCH 05/26] usb: gadget: f_ecm: eliminate abuse of ep->driver data

Since ep->driver_data is not used for endpoint claiming, neither for
enabled/disabled state storing, we can reduce number of places where
we read or modify it's value, as now it has no particular meaning for
function or framework logic.

In case of f_ecm, ep->driver_data was used only for endpoint claiming
and marking endpoints as enabled, so we can simplify code by reducing
it.

Signed-off-by: Robert Baldyga <r.baldyga@...sung.com>
---
 drivers/usb/gadget/function/f_ecm.c | 31 +++++++------------------------
 1 file changed, 7 insertions(+), 24 deletions(-)

diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
index 7b7424f..4abca70 100644
--- a/drivers/usb/gadget/function/f_ecm.c
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -541,24 +541,21 @@ static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 		if (alt != 0)
 			goto fail;
 
-		if (ecm->notify->driver_data) {
-			VDBG(cdev, "reset ecm control %d\n", intf);
-			usb_ep_disable(ecm->notify);
-		}
+		VDBG(cdev, "reset ecm control %d\n", intf);
+		usb_ep_disable(ecm->notify);
 		if (!(ecm->notify->desc)) {
 			VDBG(cdev, "init ecm ctrl %d\n", intf);
 			if (config_ep_by_speed(cdev->gadget, f, ecm->notify))
 				goto fail;
 		}
 		usb_ep_enable(ecm->notify);
-		ecm->notify->driver_data = ecm;
 
 	/* Data interface has two altsettings, 0 and 1 */
 	} else if (intf == ecm->data_id) {
 		if (alt > 1)
 			goto fail;
 
-		if (ecm->port.in_ep->driver_data) {
+		if (ecm->port.in_ep->enabled) {
 			DBG(cdev, "reset ecm\n");
 			gether_disconnect(&ecm->port);
 		}
@@ -618,7 +615,7 @@ static int ecm_get_alt(struct usb_function *f, unsigned intf)
 
 	if (intf == ecm->ctrl_id)
 		return 0;
-	return ecm->port.in_ep->driver_data ? 1 : 0;
+	return ecm->port.in_ep->enabled ? 1 : 0;
 }
 
 static void ecm_disable(struct usb_function *f)
@@ -628,14 +625,11 @@ static void ecm_disable(struct usb_function *f)
 
 	DBG(cdev, "ecm deactivated\n");
 
-	if (ecm->port.in_ep->driver_data)
+	if (ecm->port.in_ep->enabled)
 		gether_disconnect(&ecm->port);
 
-	if (ecm->notify->driver_data) {
-		usb_ep_disable(ecm->notify);
-		ecm->notify->driver_data = NULL;
-		ecm->notify->desc = NULL;
-	}
+	usb_ep_disable(ecm->notify);
+	ecm->notify->desc = NULL;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -750,13 +744,11 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 	if (!ep)
 		goto fail;
 	ecm->port.in_ep = ep;
-	ep->driver_data = cdev;	/* claim */
 
 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc);
 	if (!ep)
 		goto fail;
 	ecm->port.out_ep = ep;
-	ep->driver_data = cdev;	/* claim */
 
 	/* NOTE:  a status/notification endpoint is *OPTIONAL* but we
 	 * don't treat it that way.  It's simpler, and some newer CDC
@@ -766,7 +758,6 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 	if (!ep)
 		goto fail;
 	ecm->notify = ep;
-	ep->driver_data = cdev;	/* claim */
 
 	status = -ENOMEM;
 
@@ -820,14 +811,6 @@ fail:
 		usb_ep_free_request(ecm->notify, ecm->notify_req);
 	}
 
-	/* we might as well release our claims on endpoints */
-	if (ecm->notify)
-		ecm->notify->driver_data = NULL;
-	if (ecm->port.out_ep)
-		ecm->port.out_ep->driver_data = NULL;
-	if (ecm->port.in_ep)
-		ecm->port.in_ep->driver_data = NULL;
-
 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 
 	return status;
-- 
1.9.1

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